Gaster and Sans
by Trin Otaku
Summary: When a stranger named Gaster shows up at sans's birthday, he starts having strange flashbacks and sees him around more.
1. Chapter 1

(Hey guys! This is my first fic so I hope you enjoy! ~Trin)

sans walked around his grungy room, hearing Papyrus yell about that stupid sock in the lounge. He had left it there over a year ago, when that kid showed up. Their name was... oh gosh, sans couldn't remember. Hmmmm...

"SANS! GET DOWN HERE NOW! THE HUMAN CAME BACK!" Papyrus was yelling up to sans. Quickly, sans pulled open his door to see a familiar face standing there, holing a large box with the words 'to sans' on it. Frisk, as sans remembered his name, gave him the box and smiled. He pulled open the box, only to see a new trombone. sans had been needing one since Undyne tryed to make something other than pasta with Papyrus.

sans looked over the railing to see that the whole crew was here, except for Asgore, who had 'royal buisness' to attend to with the humans. Probably getting wasted again...

"H-happy birthday, sans!" sans heard Alplys say down in the lounge. He had totally forgot that today was his 'birthday'. Him and Papy really didn't have birthdays since they just showed up randomly. They had simply chosen days they liked best to be their 'birthdays'

sans walked down the stairs, to see the whole crew gathering around the cake. But, there was a man in a dark cloak in the corner, simply standing there. Alphys, sensing sans' confusion and curiousity, spoke up.

"He's a traveler. He needed somewhere to stay before he froze to death. hehe." Alphys could see that his confusion was still not sated. "Oh, also, h-he goes by the name Gaster.."

~TO BE CONTINUED~


	2. Chapter 2

(Hey guys! I really liked the feedback on last night's chapter, so I'm going to try and post a chapter every day! Anways, hope you enjoy ~Trin)

Gaster looked up, confused. He saw a fainted sans on the floor, and the others trying to wake him up. He pulled the hood of his cloak over his head a bit more and walked over.

"Kid's a skeleton, right?" Gaster had a hoarse and rough voice, a lot like Asgore's, but darker. "What are you guys doing? Put him up on the couch." Gaster walked over to sans' limp body, and put a slightly pixellated hand on his right shoulder. With Gaster's free hand, he waved a large number of hand signs, and sans started to glow a light blue color. sans' eyes had developed the all-too known blue pupil, and his body shook.

sans woke up on his bed, Frisk looking over him. Frisk looked excited when sans woke up, and ran downstairs to get Papyrus and Gaster. They took a while getting up there, Gaster had started a conversation about the CORE.

"Ahhh, sans, good afternoon! Now, my name is Gaster. Buuuutt, I'd like to speak to you in private please." Gaster looked around the room, seeing jazz posters and a new trombone leaning against a slightly hidden door in the corner.

"I'm not talking to you until you take that stupid cloak off. Besides," sans stopped talking for a moment and looked Gaster dead in the eye, "why would I trust someone who tried to kill monster and human-kind?"

Gaster lowered his head. "WELL. I GUESS I SHOULD LEAVE THE ROOM. COME ALONG, HUMAN." Papyrus walked out of the room, giving Gaster more room to pace in front of sans.

"I'm sorry about that..." Gaster pulled back his hood, revealing a slightly pixellated skeleton-like face. "You know, when the two royal children died, I was at work. That was the day of the... incident.

"I was walking around, me being the royal scientist and all..." He found a way to brag about it, acting a bit like Papyrus. "And someone pushed me into the core. I never saw who, but their laugh... It was the single most worst thing I've ever heard. When I fell in, my soul divided in two. Creating you and your brother. Except." Gaster created a blue flame in his hand. "You got one part of me that Papyrus didn't."

"But... How are you here?" sans looked more confused than ever.

"You have the space-time manipulation. Where do you think you got that from?"


	3. Chapter 3

(I didn't think this many people would follow this story! THANKS SO MUCH! ~Trin PS SORRY FOR NO CHAPTERS RECENTLY D: Also, I did have a question about how old sans was turning and I'd just like to say make up your own age! Thanks 3)

sans couldnt believe that Gaster knew about the space-time power, but then reassured himself that if this guy was really his creator, he'd know more about it than him.

"If you broke apart, and created me and my brother, even if you do have manipulation,you shouldn't be able to be here.." sans was so confused... "Wouldn't the fibers of your being get destroyed?"

"Yeah, well, that's where this gets interesting.." Gaster pulled up a seat and sat down, rubbing his hands together. "I have a few theories on the matter. The first one is that part of my soul survived it. I have no idea how that would've happened, though, it's a very slim possibility. The next one, and my personal favorite, is that someone brought me back. I think it may have been the royal scientist, but she would need help from someone with my powers. She would've had to take the soul and part or someone with the power- part of you, sans, and combine them. I wish I could've come back in my old form, but this will have to do. So, sans, did you take part in the experiments?" Gaster looked at sans with a meaningful look.

sans remained quiet and looked down. He put his hand under his eyes, looking at the little chipped mark in the bone. "I had no choice, ok?" sans snapped at Gaster, Gaster falling back in his seat, surprised. "The king - King Asgore - He told me I had to do it if I wanted my brother to live. He needed you back for some kind of... ressurection." Gaster knew what sans was talking about. "This is about his son, isn't it?" sans looked up at Gaster. "I know what to do. I'll take you to Alphys."

"Listen, kid, you gotta get me somethin to drink. This place is sweltering." Gaster complained, obviously he hasn't been in Hotland for a while.

"Calm down. We're almost there." sans said, as they walked into a large white building with large words spelling out LAB above the door. There inside, they saw a mess of ramen cups and MewMewKissieCutie collectibles. Gaster looked up from the floor to see a yellow dinosaur-looking girl with glasses, an anime t-shirt, and jeans on. "Gaster, this is Alphys. Alphys, you know the deal."

"H-hi, Gaster. I know you don't know me and this is a terrible way to get aquainted, but hold out your arms and close your eyes." Alphys said, grabbing a cyringe from the table. "We'll moniter your dreams. This may hurt a little,haha..." Alphys injected the needle into Gaster,then everything went black.


	4. Chapter 4

Gaster opened his eyes, expecting to see sans and Alphys, but instead seeing the king's two kids before they had died. Then, he saw himself and the king talking. _I must be in a dream... or a memory._ He thought. "The middle of the Core is going to explode, your majesty. I need to go in and save it." Gaster heard himself say to the king.

"You're my best scientist! I can't have you risking your life to save everyone else. Besides, I need you to come up with a vaccine. My child... they're sick, and Asriel will not forgive me if I let them die." Asgore said, but Gaster could see the greed in his face He was confused as to why he didn't notice it back then. But right at that moment, the king's child collapsed.

The king rushed Gaster into the room where the sick child was sleeping. "Gaster... you have to make a vaccine" The king was about to break down.

"I-I'm sorry,your majesty... but I-I have to go save the Core..." Gaster ran out of the room, and ran all the way to the Core's center building. "I have to do this..." Gaster said to himself. ' _Why am I doing this? I don't remember a thing about THIS...'_ Gaster watched himself jump into the center, his eyes turning blue and a protective fireball forming around him. Gaster watched his soul burn up in the Core... but the Core stopped. Everything stopped. Gaster stopped falling, and everything was still. _What did I do?_

Then, Gaster woke up.


End file.
